We humans love to scare ourselves with horror movies, especially as Halloween approaches, but the natural world contains plenty of real-life horrors to keep us awake at night.

Australian science blogger Becky Crew's book "Zombie Birds, Astronaut Fish, and Other Weird Animals" chronicles the gory, fascinating and perverse activities of animals and insects.

Filled with R and even X-rated material, this is not a book to leave lying about the house for youngsters or in-laws to discover.

Take a sweet-looking, olive and yellow bird called the great tit for example. When tiny pipistrelle bats wake from hibernation, their calls attract great tits, which invade the bats' caves, capture the bats, crack open their skulls and feed on their brains, Crew writes.

While great tits copy the behavior of brain-eating zombies from horror flicks, the northern grasshopper mouse behaves like a werewolf.

This mouse is known to "mimic the posture of a wolf, throwing back its little head to point its nose to the sky and howl," Crew explains.

The northern grasshopper mouse feeds on tarantulas, scorpions and other rodents. As a carrier of the plague bacterium, the mouse has decimated the populations of five prairie dog species with the Black Death.

The Kenyan jumping spider would be the good guy in a movie. This spider is a vampire killer, preying on blood-filled mosquitoes. Scientists are investigating the possibility of using the spiders to combat malaria, which is spread by mosquitoes, Crew reports.

If monsters are on the loose, you might want a hagfish or European roller nestling by your side.

The hideous hagfish, which lives on ocean bottoms, can secrete five gallons of mucus to smother the mouths and gills of predators. Researchers believe the hagfish may also be able to slime its prey.

When threatened, the young of European roller birds vomit a pungent orange liquid on themselves.

The lifestyle of another ocean-dweller, the tongue-eating isopod, is enough to induce nightmares.

This bug-like parasite can burrow into a fish through its gills, attach itself to the fish's tongue, then suck blood until the tongue withers away to nothing.

"Grasping the inside of the fish's mouth, the isopod plays the part of a replacement tongue, feeding off the scraps of food that enter its mouth," Crew writes.

In addition to gore and violence, horror movies usually have sex scenes to titillate audiences. Crew details the activities of several different species that would prove inspiring to makers of pornography.

Sometimes reproduction and violence go hand-in-hand in the natural world.

Black-lace weaver spider hatchlings eat a second batch of eggs laid by their mother — in effect gobbling up their younger brothers and sisters. Then the spiderlings eat their mom.

If a murderous mad scientist puts you in a cage, make friends with a lab rat. In experiments, a majority of rats chose to release fellow rats from restrainer devices.

When offered the choice of chocolate chips or freeing another rat, half of rats still chose to release their friends — showing that compassion and cooperation can sometimes win out in the natural world.